Prosthesis

ABSTRACT

The invention relates to prostheses for amputated patients. The shaft of the prosthesis ( 10 ) consists of an outer shell ( 11 ) and a concentric inner shell ( 11′ ). Both shells are provided with longitudinal slits ( 12, 12′ ) which are staggered in relation to each other and extend essentially in the axial direction. The diameter of the shaft ( 10 ) of the prosthesis can be adjusted by means of tightening elements ( 13, 14 ). An adapter ( 20 ) is fixed in the shaft of the prosthesis ( 10 ) in such a way that the height of said adapter can be adjusted. A conical bearing surface for the stump of the limb is provided on the upper side of the adapter ( 20 ), a holding element ( 29 ) for fixing an artificial limb is provided on the lower side of the same, and a coupling is provided inside the adapter for detachably fixing the coupling pin ( 41 ) of a commercially available silicone liner ( 40 ).

TECHNICAL FIELD

[0001] The invention relates to prostheses according to the preamble ofclaim 1, essentially comprising a silicone liner with a coupling pin, aprosthesis shaft adapted to a limb stump, provided with longitudinalslits in some areas, the diameter being adjustable by means oftightening elements, and a holding device to connect artificial limbswith the shaft of the prosthesis.

CONVENTIONAL ART

[0002] It is the purpose of prostheses to replace as best as possiblelimbs that were lost through an accident or illness. To temporarilyattach prostheses, for example artificial hands or feet, to a limbstump, special prosthesis shafts are used, which must be anatomicallyfitted to the limb stump. The attachment is commonly achieved by avacuum between the prosthesis shaft and the limb stump or between thelimb stump and a silicone liner.

[0003] Prosthesis shafts are made of metal, wood or cast resin. Thereare shafts of longitudinal or cross-oval shape, full-contact shafts,with a valve, or a silicone liner. With amputations below the kneejoint, the prosthesis shafts are somewhat triangle-shaped, with supportdevices on the bone structure.

[0004] Since the prosthesis shafts must be fitted to the limb stump asexactly as possible, in order to generate and maintain the vacuumproviding the firm attachment, the shafts are always custom-madeproducts, which also must provide perfect pressure distribution of theload onto the entire stump area so that the stump can optimally transferthe body weight and other forces. Since initially after an accident oramputation, there is swelling of the limb stump within a few days orweeks, which then goes down again, but from a medical and orthopedicview, the patient should be fitted with a prosthesis as quickly aspossible, at times several prosthesis shafts must be fabricatedindividually during the rehabilitation and adjustment period alone. Thisis unsatisfactory because of the expenditure of time and particularlymoney connected therewith.

[0005] It goes without saying that there has been no lack in attempts torectify this situation. For example, inflatable air chambers have beenarranged between the prosthesis shaft and the limb stump, see WO00/23016. However, it was determined very quickly, that the gripattachment of the prosthesis to the limb stump was clearly reduced. Inparticular, the utilization value of the prosthesis was greatly reduced,since it is not solidly connected to the limb stump anymore.

[0006] To circumvent this problem, DE 27 18 395 C suggests filling airchambers with little balls. The ball-filled air chambers are supposed toadapt to the contours of the limb stump. By evacuating the air chambers,the balls are supposed to be molded into their actual, more or lesswell-adapted, position on the limb stump. Although it was good thinking,this construction did not prove itself and was not successful inpractice.

[0007] From DE Patent 314 985, which was published in 1919, a prosthesisshaft is known, which is made of an inner and an outer shell. The innerand outer shell consists of individual lamellae, which are connected toeach other by a rivet, in such a way that the diameter of the inner andouter shell can be modified. To alter the diameter of the inner andouter shell, several tightening strings are provided. However, afterclosing the tightening strings for the outer shell, the tighteningstrings for the inner shell are no longer accessible, that is, theirfasteners are not accessible anymore. Attaching and detaching of such aprosthesis shaft is, therefore, extremely cumbersome and time-consuming.In addition, prosthesis shafts made of lamellae cannot develop a vacuumfor firm attachment to the limp stump.

[0008] A further, dual-shell prosthesis shaft is known from DE Patent323 671, which was published in 1920. Here, too, an inner and outershell consist of lamellae, whereby the lamellae of each shell aremutually connected by a rivet in such a way that it allows modificationof the diameter with the help of tightening strips. Furthermore, anupper part of the lamellae of the inner shell are movably connected withthe lamellae of the outer shell. The object of this construction is toavoid gaps between the individual lamellae. This construction also didnot succeed in practice.

[0009] From the orthopedic practice it is known that limb stumps notonly change in width but also in length. This is, for example, the casewhen the end of the limb stump, which is in direct contact with theprosthesis and, for example, in the case of an upper thigh prosthesis,must bear the entire body weight of the patient, gets infected andswelling occurs. A change in length can also occur when the swollentissue is healing after an amputation or operation, and the swellinggoes down. The limb stump then no longer sits correctly with a conicalbearing surface that is provided in each prosthesis shaft and can, forexample, no longer optimally transfer the body weight to the prosthesis.Also, in this case, new prosthesis shafts must be fabricated or the oldprosthesis shafts must be modified. This is unsatisfactory.

[0010] From DE 82 16 840 U a prosthesis shaft is known, whereby a heightof the conical bearing surface for the limb stump is adjustable. Theheight adjustment is done using level or wedge mechanics, which can bemanipulated from the outside by the patient using a crank or somethingsimilar. Height adjustment with a built-in electric motor, possiblybattery-operated, is also suggested. Since the height adjustment must beinstalled in the custom-made prosthesis shaft, it must be enlarged andmodified accordingly. This increases the expenditure of time and money.

[0011] As previously mentioned, each prosthesis shaft must be fabricatedin such a way that it transfers the forces optimally to the limb stump.To accomplish this, the prosthesis shaft must be suitably inflexible. Inorder to be able to adjust the diameter, the prosthesis shaft must beflexible. Flexibility directed towards the diameter can be achieved byconstruction with lamellae, as described in the German patents listedabove. The connection between the lamellae with only one rivet, however,has the disadvantage that it weakens the stability of the prosthesisshaft.

ILLUSTRATION OF THE INVENTION

[0012] It is therefore an object of the present invention to disclose aprosthesis as previously described, which can be fabricated simply andthanks to prefabrication can be produced in greater series,cost-efficiently, having a great solidity and fits within predeterminedlimits to limb stumps, whereby a diameter and length can be changed.

[0013] The problem is solved with a prosthesis with the features ofclaim 1, essentially comprising

[0014] a silicone liner with a coupling pin,

[0015] a prosthesis shaft

[0016] fitted to a limb stump,

[0017] provided with longitudinal slits in some areas,

[0018] and adjustable in diameter using tightening elements,

[0019] and a fastener for connecting an artificial limb with theprosthesis shaft,

[0020] the longitudinal slits are bridged over,

[0021] the prosthesis shaft has a concentric band,

[0022] inside the band, a cylindrical adaptor is height-adjustablymounted,

[0023] the adaptor

[0024] has

[0025] at its upper end a bearing surface for the limb stump or an endof the silicone liner,

[0026] and a fastener at the bottom,

[0027] and on its inside

[0028] a coupling for detachable fixation of the coupling pin at the top

[0029] and mechanics for loosening the coupling at the bottom.

[0030] According to the present invention, the flexibility of theprosthesis shaft is achieved by the longitudinal slits, theinflexibility of the slitted prosthesis shaft by bridging thelongitudinal slits. Thanks to the considerably improved stiffness, thewall strength can be decreased and thus, comfort of wearing can beincreased. The adjustability of the diameter of the prosthesis shaftmakes it possible, through industrial prefabrication of only a few basicmodels for the right and the left side of the body, respectively, tomeet the demand for most of the common initial provisions. Moreover, theprosthesis can be attached and detached quickly and comfortably. Its fitis impeccable.

[0031] To attach the prosthesis, the silicone liner is first rolled overthe limb stump. Next, the limb stump and silicone liner must be insertedinto the prosthesis shaft of the prosthesis, until the end of the limbstump or the silicone liner rests on the conical bearing surface,whereby the coupling pin is completely immersed in the coupling. Whenthe prosthesis shaft fits very tightly, for example, because the limpstump is slightly swollen, it can happen with a one-piece prosthesisshaft that the optimal position is not achieved. For this reason,current commercial prostheses have an installed freewheeling gear wheel,which the wearer of the prosthesis can manipulate from the outside witha coin. This gear wheel interacts with the profiled coupling pin, whichin this way is pulled into the prosthesis shaft. In contrast thereto,with the prosthesis of the present invention, such a construction isentirely superfluous, because any limb stump can be inserted into theopen prosthesis shaft without any difficulty. The same is true for thedetachment of the prosthesis.

[0032] As soon as the patient no longer needs the interim prosthesis ofthis invention, it can be cleaned and used for the next patient. Thereduction of resources and expenses connected therewith is, to date,unmatched.

[0033] The ability to industrially prefabricate the interim prosthesisof the invention in few sizes is, by the way, only possible because theprosthesis of this invention not only has a width adjustment but also alength adjustment in the form of a cylindrical adaptor, which isinserted, more or less as needed, into the prosthesis shaft. Thisadaptor has, at its top, the conical bearing surface for the limb stump,at its bottom the standard coupling for fastening an artificial limb,and on its inside the mechanics for detachably fastening the couplingpin and commercial silicone liner.

[0034] According to a first embodiment of the invention, thelongitudinal slits are at least partially bridged with a flexiblematerial, which forms ripples and folds. These ripples and folds can bemade of the same material that the prosthesis shaft is made of, wherebythe flexibility is achieved by careful selection of wall strength andshape.

[0035] As an alternative, there is the possibility to bridge thelongitudinal slits with a rubber-like material, in particular siliconerubber.

[0036] In a preferred embodiment of the invention, the prosthesis shaftis formed by two concentric shells. Therewith, an inner area of theouter shell is essentially the same as an outer area of the inner shell,the longitudinal slits of the outer and inner shells are staggered inrelation to each other, and the diameter of both shells is mutuallyadjustable by tightening elements. Additionally, the inner and outershells have a concentric band, which holds the adaptor.

[0037] This embodiment of the invention has a great stiffness, togetherwith low weight and high comfort in wearing, even with minimal wallstrengths of the shells, which fit each other perfectly, comparably tothe skins of an onion. Since both shells are held in place by one typeof tightening element, such a prosthesis is very quickly attached anddetached. Furthermore, this embodiment of the invention can beindustrially prefabricated with a few basic models, which reduces thecost of the prosthesis even further.

[0038] According to an advantageous embodiment of the invention, thecoupling pin on the silicone liner is a plain cylinder, and the couplingincludes a clamping plate and an opening that fits the coupling pin,whereby the clamping plate is pivotably positioned on an axis and ispivoted into a clamp position by springs. Such a smooth coupling pin isnot only simpler and more cost-effective than a profiled coupling pin,but is also in all cases easy to detach, as opposed to conventionalprofiled pins, which are held by a free-wheeling gear wheel, which afterprolonged wearing of the prosthesis is under enormous pre-stress andtends to jam.

[0039] Advantageously, the clamping plate, which is positioned in theupper part of the adapter because of the shortness of the coupling pin,is connected by a rope or a spoke to a manual lever, which is positionedat the lower end of the adapter and is thus easily accessible at everyheight adjustment. Basically, this coupling construction also works withthe commercial profiled coupling pins, however, the height adjustment isthen not progressive.

[0040] Advantageously, the adapter includes two parts, which are heldtogether by screws or the like. In an advantageous embodiment, one ofthe fastening screws can be simultaneously used as a pivotal axis forthe clamping plate of the coupling.

[0041] The connection between the inner and outer shells and the adapteris preferably performed with a clamp connection. In order to achieve asafe clamp connection between the prosthesis shaft and the adapter it issuggested to slit the band elastically.

[0042] In a preferred embodiment, the clamp ring itself has a flange formounting the tightening screws.

[0043] As mentioned, the adaptor of this invention allows adaptation tolimb stumps of varying lengths or to those that had to be shortened formedical reasons, without having to change the actual prosthesis shaft.Only the connection rod between the artificial limb and the conventionalfastener, which is positioned at the lower end of the adapter, has to beextended.

[0044] According to an embodiment of the invention, the mechanics fordetaching the coupling includes a manual lever, which is retractable, sothat it does not get in the way when the prosthesis is being worn.

[0045] Advantageously, the shells of the prosthesis shaft are made offiber-reinforced, particularly carbon fiber-reinforced, plastic, wherebythe reinforced fibers essentially extend in an axial direction so that,as desired, there is a high stiffness in an axial direction andsufficient flexibility in a circumferential direction.

[0046] In a case, where the longitudinal slits in the outer or innershell bother the patient, these can, at least partially, be filled witha flexible material. This flexible material can be a rubber-likesubstance, for example, silicone rubber.

[0047] In order to be able to attach and detach the prosthesis of theinvention very quickly, the tightening element is preferably atightening band with a toggle latch closure.

[0048] To prevent vascular congestion in the limb stump because thetightening band is too tight, or because the prosthesis does not fitproperly because the tightening band is not tight enough, the tighteningelement is equipped with a length adaptation device, which is to beoperated only by an expert, for example, an orthopedic technician. Thus,the patient can only open and close the tightening element.

[0049] Lastly, one should make sure that inner shell and outer shell,adapter, and in some cases, clamp ring are safeguarded against twisting.

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] With the aid of the drawing, the invention in the form of anembodiment is described in more detail. Shown, in each instance purelyschematically, are in:

[0051]FIG. 1 a prosthesis shaft, which is adjustable in acircumferential and a longitudinal direction,

[0052]FIG. 2 part of the prosthesis shaft of FIG. 1 in enlarged scale,with an inserted adapter in a fully extended position,

[0053]FIG. 3 the adapter of FIG. 2 in a fully immersed position,

[0054]FIG. 4 the adapter of FIG. 2 and 3 in an opened position and

[0055]FIG. 5 various cross-sections of folds or ripples.

EMBODIMENTS OF THE INVENTION

[0056]FIG. 1 is a perspective illustration of a prosthesis shaft 10,which is anatomically fitted to a limb stump (not shown), at the bottomof which, a coupling 29 is mounted to which, if need be, an artificiallimb, for example an arm or foot prosthesis, can be attached via anextension rod.

[0057] The prosthesis shaft 10 includes an outer shell 11 and an innershell 11′. In the outer and inner shells 11, 11′, there are slits 12,12′ extending essentially in an axial direction, which are staggered inrelation to each other. In an ideal situation, the outer and inner shell11, 11′ touch each other like the skins of an onion.

[0058] When the outer and inner shell 11, 11′ is made of a carbonfiber-reinforced plastic, thinner walls and thus reduced weight can beachieved. If the reinforced fibers extend mostly in an axial direction,the shells 11, 11′ are inflexible in a longitudinal direction, andflexible in a circumferential direction.

[0059] In order to be able to adjust the diameter of the prosthesisshaft 10 having the outer and inner shells 11, 11′, two tightening bands13 including toggle catch closures 14 are provided, the width of whichcan be adjusted by a precision-adjuster (not illustrated) by a trainedtechnician. When the toggle catch closures 14 are closed, the slits 12,12′ are compressed, which causes a tight fit of the prosthesis shaft 10to the limb stump.

[0060]FIG. 1 also illustrates, purely schematically, a silicone liner40. Initially, this is put over the limb stump and fixedly attached byvacuum. On the underside of the silicone liner 40, there is provided acoupling pin 41, which interacts with a coupling. This coupling islocated inside a cylinder-shaped adapter 20, which is fixatedheight-adjustably in the prosthesis shaft 10 with the aid of a clampring 30. For this purpose, the outer and inner shell 11,11′ each have attheir lower end a concentric band 15, 15′. Thanks to a slit 16, the band15, 15′ is elastically flexible. The clamp ring 30 has a flange 31 andcan be tightened and/or loosened by tightening screws 32.

[0061]FIG. 2 shows, in an enlarged scale, a section of FIG. 1. Theadapter 20 can be seen in a completely extended condition. Furthermore,at the lower end of the adapter 20, a foldable manual lever 23 can beseen, with which the coupling located in adapter 20 can be operated.Further details will be described with the description of FIG. 4.

[0062]FIG. 3 shows the adapter of FIG. 2 immersed completely in theprosthesis shaft 10. Thus, at the upper end of the adapter 20, a conicalbearing surface 21 for the limb stump, that is, the silicone line 40,can be seen.

[0063]FIG. 4 shows the adapter 20 in an opened position. At its top, onecan see the conical bearing surface 21, on which the top of the silicone40 rests. Its coupling pin 41 is formed as a smooth cylinder and extendsthrough the bearing surface 21. The coupling includes a clamp plate 22,which is pivotably positioned around an axis 25, and whichsimultaneously serves as a connection screw. Springs 26 pivot the clampplate 22 into a clamp position so that the coupling pin 41 can beinserted without a problem and at the same time is safeguarded againstunintended detachment. Additional screws 31, 32 connect parts of theadapter 20.

[0064] To detach the clamp plate 22, the manual lever 23 is used, whichis connected with the clamp plate 22 via a coupler rod 24 and/or acoupler rope located inside the adapter 20. When the patient moves thelever 23 downward, the clamp plate 22 is pivoted downward from its clampposition, as illustrated in the drawing, to a neutral position, and thepatient is able to remove the coupling pin 41 with silicone liner 40 andlimb stump from the adapter 20 and/or prosthesis shaft 10, as soon asthe tightening bands 13, 14 are opened. The clamp plate 22 is anordinary, hardened steel plate with a bore, which corresponds with thediameter of the coupling pin 41. This simple construction is extremelydurable and safe to operate.

[0065]FIG. 5 shows, purely schematically, three possible cross-sectionsof folds and/or ripples, with which the longitudinal slits 12 can bebridged. These cross-sections are, seen from top to bottom, of zig-zag,omega and dovetail shape.

1. Prosthesis, essentially comprising a silicone liner (40) withcoupling pin (41), a prosthesis shaft (10), fitted to a limb stump,provided with longitudinal slits (12) in some areas, and adjustable indiameter by means of tightening elements (13, 14) and a holding element(29) for connecting an artificial limb with the prosthesis shaft (10),characterized by the features: the longitudinal slits (12) are bridged,the prosthesis shaft (10) has a concentric band (15), in the band (15) acylindrical adapter (20) is height-adjustably installed, the adapter(20) has a bearing surface (21) at the top for the limb stump and/or theend of the silicone liner (40) and the holding element (29) at thebottom and has on its inside a coupling (22-26) for the detachablefixation of the coupling pin (41) at the top and mechanics (23) fordetaching the coupling (22-26). 2 Prosthesis according to claim 1,characterized by the feature: the longitudinal slits (12) are at leastpartially bridged by a flexible material, which forms ripples or folds.3. Prosthesis according to claim 1 or 2, characterized by the features:the prosthesis shaft (10) is formed by two concentric shells (11, 11′),an inner surface of the outer shell (11) is essentially the same as anouter surface of the inner shell (11′), longitudinal slits (12, 12′) ofthe outer and inner shells (11, 11′) are staggered in relation to eachother, the diameter of both shells (11, 11′) are mutually adjustable bya tightening element (13, 14), the outer and inner shells (11, 11′) havea concentric band (15, 15′).
 4. Prosthesis according to one of claims 1to 3, characterized by the features: the coupling pin (41) is a smoothcylinder, the coupling comprises a clamp plate (22) with an opening,which is fitted for the coupling pin (41), an axis (25), on which theclamp plate (22) is pivotally positioned, and springs (26), which pivotthe clamp plate (22) into a clamp position.
 5. Prosthesis according toone of claims 1 to 4, characterized by the features: the adapter (20)includes two parts, the axis (25) simultaneously serves as a connectionelement.
 6. Prosthesis according to one of claims 1 to 5, characterizedby the feature: the band (15, 15′) of the shells (11, 11′) iselastically slitted.
 7. Prosthesis according to one of claims 1 to 6,characterized by the feature: a clamp ring (30) is mounted onto the band(15, 15′).
 8. Prosthesis according to claim 7, characterized by thefeature: the clamp ring (30) has a flange (31) for mounting clamp screws(32).
 9. Prosthesis according to one of claims 1 to 8, characterized bythe feature: the mechanics for detaching the coupling (22-26) include amanual lever (23), the manual lever (23) is foldable.
 10. Prosthesisaccording to one of claims 1 to 9, characterized by the feature: theshells (11, 11′) are made of fiber-reinforced, particularly carbon fiberreinforced, plastic.
 11. Prosthesis according to claim 10, characterizedby the feature: the reinforced fibers extend essentially in an axialdirection.
 12. Prosthesis according to one of claims 1 to 11,characterized by the feature: the slits (12, 12′) in the outer shell(11) and/or the inner shell (11′) are at least partially bridged by arubber-like material, particularly silicone rubber.
 13. Prosthesisaccording to one of claims 1 to 12, characterized by the feature: thetightening element has a tightening band (13) with a toggle latchclosure.
 14. Prosthesis according to one of claims 1 to 13,characterized by the feature: the tightening element (13, 14) has alength adjustment, which must only be operated by a trained technician.15. Prosthesis according to one of claims 1 to 14, characterized by thefeature: inner shell (11′) and outer shell (11), adapter (20) and, asthe case may be, clamp ring (30), are safeguarded against contortion.